New applications to use paintball guns or projectile launchers have become more popular in recent years. For example, paintball guns can be used in professional trainings, such as trainings for soldiers, policemen, security personals, and/or athletic participants. The success of training and/or competition may largely depend on how closely the paintball guns mimic and/or resemble the real firearms or semi-automatic hand guns.
A drawback associated with a conventional paintball gun or marker is that its internal construction is quite different from conventional firearms. For example, the physical construction and appearance of a conventional paintball gun are different from typical real firearms and/or guns partially because internal pressurized propelling system of a paintball gun which uses valve, striker, and bolt is different from a conventional gun. Accordingly, it is often difficult to replace the internal components of a real firearm with the internal components of a paintball gun.